Method and apparatus for everting under pressure a tubular probe into a body cavity



March 18, 1969 D. SILVERMAN 3,433,214

METHOD AND APPARATUS FOR EVERTING UNDER PRESSURE A TUBULAR PROBE INTO ABODY CAVITY Filed Oct. 20, 1965 Sheet of 2 IIIIIIIIIIIIIIIIII INVENTOR.

March 18. 1969 D. SILVERMAN 3,433,214

METHOD AND APPARATUS FOR EVERTING UNDER PRESSURE A TUBULAR PROBE INTO ABODY CAVITY Filed Oct. 20, 1965 I Sheet 2 of 2 INVENTOR.

United States Patent O 26 Claims ABSTRACT OF THE DISCLOSURE Thisinvention concerns an instrument for the placement of a sampling,inspecting or treating device Within an extended tubular cavity. Thedevice consists of a tubular casing, a flexible thin-walled tubularprobe inside of the casing with the inside end closed and outside endsealed circumferentially over a first end of the casing. The second endof the casing is closed. A reservoir of liquid is provided that can beraised above and lowered below the level of the casing, The reservoir isconnected by conduit to the casing. When the reservoir is raised, liquidflows into the casing causing the tubing to evert out of the end of thecasing. When the reservoir is lowered, liquid flows out of the casing,causing the tubing to be inverted back into the casing.

This invention relates to the placement of a sampling, inspecting, ortreating device within an extended cavity or tubular chamber that mayhave linear and nonlinear portions. Because of the nature of the cavitya rigid mechanical device could not be introduced into such a cavity anda thin flexible member is not self-sustaining and cannot be pushed intothe cavity.

More specifically, this invention relates to the art of medicalapparatus including those instruments which are concerned with thesampling, inspecting, and treating of the walls of internal bodycavities. Further, this invention is an improvement on that embodied inmy US. Patent 3,168,092, issued Feb. 2, 1965, and entitled, MedicalProbing Instrument Having Flexible Extrudable Tubing Adapted To BeExtraverted Under Pressure Into a Body Cavity.

Although the apparatus of my patent is useful for the purposes intended,the present invention extends the application to smaller diametercavities and permits the manipulation of a wider variety ofinstrumentation. It also extends the techniques which may be followed inpracticing the invention.

Briefly described, my invention utilizes an elongated, fluid confiningchamber or casing having circumferential side walls and two endclosures, One end closure of the tubular casing has an opening which isadapted to be placed in communication with the cavity. This opening alsopermits the introduction and/or the retrieval of a thin wall flexibletubing to be introduced into the cavity. A length of such tubing incollapsed form has one end closed and is placed within the casing. Oneend of the tubing remote from the cavity is closed. The other end of theflexible tubing is open and is secured circumferentially to the openingin the end closure of the casing. The entire length of tubing comprisesthe end closure for that end of the casing.

Means for introducing a fluid within the casing and about the flexibletubing stored therein is provided and such fluid displaces the tubingprogressively from the casing by everting the lead end which is thefirst to be extruded from the casing.

Thus, the collapsible thin wall flexible tubing is progressivelyextraverted and progressively projected from "Ice the easing into thecavity as pressure and/or displacement fluid is applied to the annulusbetween the collapsed tubing and the casing wall. Means are provided formaintaining the displacing fluid within the casing under the maintainedpressure and this can include both control and indicator means.

As will become apparent, as the tubing is being theextraverted/extruded, the trailing end of the flexible tubing moves outof the casing and into the extruded inflated tubing. The trailing endmay carry a retrieval means and/or may transport into the cavity andwithin the extraverting tubing a wide variety of instruments which maysample, inspect, or treat the areas within and adjacent the cavity. Thecollapsed tubing within the casing may contain medicating, sampling,and/ or opaquing materials which are brought in direct contact with thewalls of the cavity when the flexible tubing is extraverted asdescribed. Such materials Within the collapsed tubing might alsocomprise adhesive, adsorbent or other materials whereby samples of thecavity wall can be obtained.

These and other new and novel techniques and benefits derived from theuse of my invention will become apparent as my description thereofproceeds with reference thereof from the attached drawings, wherein:

FIGURE 1 illustrates one embodiment of this invention in which hydraulicmeans are used to extravert and retrieve the probe.

FIGURE 2 illustrates another specialized embodiment of this inventionwhich is completely disposable.

FIGURES 3 and 4 show alternate embodiments by which the probe is sealedto the casing.

FIGURE 5 illustrates an embodiment employing a probe comprising twoseparate tubings.

FIGURES 6, 7, and 8 illustrate two embodiments which utilize a constantvolume liquid system. FIGURES 7 and 8 show one in which the probe isextraverted by reducing the cross-section of the casing, and FIGURE 8illustrates one in which the probe is extraverted by reducing the lengthof the casing.

In FIGURE 1 is shown one embodiment of this invention. The casingcomprises a tubular element 15, which may, for convenience have a firstend portion 15, of reduced diameter to accommodate the turned back cuff19 of the tubular thin-walled plastic probe 18, and the nozzle or nosepiece 17. The other end of the casing is closed ofi by a closure, whichcan be an integral part of the tubular portion 15, or, as illustrated,it can be a rigid plug pressed or fastened into the casing. It is alsopossible to provide a compliant, penetratable, self-sealing closure,such as is illustrated in my copending application, Ser. No. 498,462,filed Oct. 20, 1965, entitled Method and Apparatus for Placing in andRetrieving a Tubular Probe from a Body Conduit. Such a self-sealingclosure permits the passage through and sealing through the closure ofthe pipes 22, 20, etc.

In FIGURE 1 the closure is shown as a rigid wall having insertedtherethrough two small diameter pipes 20 and 22. Pipe 20 serves, withvalve 21 to bleed air from the space 30 when it is being filled withliquid. Pipe 22 serves as a conduit through which fluid is passed intothe casing to displace and extravert the tubing probe. The probe 18 is alength of thinwalled flexible tubing placed in collapsed form into thecasing. The inner end is first placed over and sealed to, by means ofclamp 27, a long small diameter cylindrical instrument 26. Theinstrument illustrated is a flexible semi-rigid walled tube 26. However,any other type of instrument can be used, as illustrated in my US.Patent 3,168,092, issued Feb. 2, 1965. The outer end of the tubing 18 isturned back over the end 15 of the casing to form a tight fitting cuff19. This is locked in position by the nozzle or nose piece 17,

The instrument 26 and the tubing 18 are of such length that theinstrument 26 is passed through an opening 24 in the end closure 16.Resilient means such as the O ring 25 are used to seal around thesurface of the instrument as it moves into and out of the casing. Othermeans to seal the cylindrical instrument 26 are possible as is Wellknown in the art.

A container or reservoir 29 of liquid 33 is carried by bracket 34 on acolumn 35 which is supported by a base 36. The bracket can be moved upor down, as shown by arrows 32 by means shown schematically as a leadscrew 37 and motor 38. Of course, other means, including hand operatedmeans, can be used.

The container 29 has an outlet pipe 43 connected to flexible conduit 28,which is a continuation of the conduit 28 attached to pipe 22. Theconduit can be simple as a length of rubber tubing.

The level 31 of the liquid 33 is shown by index arrow 39, whichindicates against scale 42 on strip 40. This scale reads plus forpositions above the zero level line 41 and minus for positions below.The level of the line 41 is substantially the level of the axis of thecasing 15. The reading of the scale opposite the index is the distance(in inches or centimeters) of the liquid level above or below the casing15, and is a measure of the hydrostatic pressure in the casing. Thereading on scale 42 for the position of the index or resorvoir might becalled the extraverting index, since the rate at which the probe isextraverted is a function of this reading. Similarly the rate ofintroversion and retrieval is a function of the negative pressure orsuction due to the lower position of the reservoir when the extravertingindex is minus or negative.

In use, the reservoir is placed at a negative extraverting index (lowerthan the level of the casing). The probe 18 and instrument 26 are put inplace and the nose piece 17 placed in position. Then the reservoir israised. As the index approaches zero, liquid will begin to flow from thereservoir into the casing. The valve 21 is opened so that the air in thespace 30 can be bled off as the liquid fills the casing. The reservoiris positioned at a desired plus" index value and left there. Liquidcontinues to flow into the casing. When the casing is full and the valve21 closed, the instrument is positioned so that the nose piece is at themouth of the cavity, and the liquid flowing from the reservoir thenextra-verts the probe out through the nose piece, turning it inside outas it goes into the cavity. As the probe moves out, the end at 27 alsomoves out and carries with it the attached instrument 26. When the probeis fully extraverted into the cavity, the instrument 26 is in the cavityin position for use.

When the examination or treatment of the cavity is completed, the probeis retrieved. There are two ways to do this. One way is to keep theextraverting index the same as for the eversion or extraversion step,and retrieve the probe by pulling on the instrument end 26, exposedoutside the closure 16. The other way is to lower the reservoir 29 toposition 29' with a negative index, and cause the liquid to flow out ofthe casing, causing the probe to be retrieved into the casing. While Ihave shown an instrument 26 attached to the inner end of the probe 18,in many areas of use of this invention, a probe will be used without aphysical means attached, by means of which it can be introverted backinto the casing. With a physical retrieval means such as a cord, rod, orinstrument attached to the probe, the retrieval is best accomplished bykeeping the reservoir at a positive index while physically retrievingthe probe by pulling on the retrieval means. When there is no physicalretrieval means, the probe is retrieved by lowering the reservoir to anegative index position, and the higher pressure outside the probe thaninside the casing will cause it to be introverted into the casing.

The magnitude of the extraversion index to be used in any specificoperation is a function of the length, thickness, and diameter of theprobe, the material of which the probe is made, and the condition of thewalls of the cavity (such as whether the walls of the cavity havecollapsed and pressure is required to lift or spread them). In any case,the pressure in the casing is under the precise control of the operatorby shifting the position of the reservoir, as needed. Because of thelarge area of liquid surface in the reservoir, the level 31 changes butlittle as liquid flows into or out of the chamber. This system does notrequire the normal use of valves, pressure indicator, or pump as inother systems, and still provides smooth control of the displacement,eversion and inversion processes.

In FIGURE 2 is shown another embodiment which is a simple, specializedapplication of the embodiment f FIGURE 1. Tube 45 which can be a fairlyrigid, thickwalled plastic tube is the casing. This tube 45, perhapswith an additional nose piece or nozzle 46 comprises a disposable enematube, or the like. Inside the casing 45 is a length of collapsedthin-Walled tubing 47, which is sealed 48 over the end of casing 45. Atits inner end, the tubing 47 is fitted with and sealed over a shortpiece of tube 49, which, in effect, is a perforated plug. The casing 45is connected by inlet 51 to conduit 52 connected to reservoir 29, filledwith liquid 33. The mounting of the reservoir 29, and index 39 and otherfeatures are similar to the same features of FIGURE 1, although somedetails have been omitted from FIGURE 2 for convenience.

The enma tube 45 is inserted into the colon. The reservoir 29 is raised.Liquid 33 flows through conduit 52 into casing 45, displacing andextruding the tubing 47 to its full length. While there will be someflow of liquid through the bore 53 of tube 49, if the flow of reservoirliquid is great enough (large positive extraverting index) the tubingwill be extraverted rapidly. The length of the tubing 47 can be anythingdesired so as to place the point of water entry some distance into thecolon. Liquid flows from the reservoir 29 through conduit 52, casing 45,extruded tubing 47, and tube 49 into the colon, so as to flush down thecolon. When inflow of water is to be stopped, the reservoir can belowered, or a clamp placed on conduit 52, as is well known. The tubing47 can be withdrawn into the casing 45 by means such as described inconnection with FIGURE 1, or it can be left extruded and the assembly of45 and 47 pulled out of the colon.

In FIGURES 1 and 2, I show the tubing clamped between the casing andnozzle, or nose piece. A preferred embodiment is indicated in FIGURE 4in which the tubing 47 is permanently fastened to the casing 45, such asby molding or cementing along the circumferential contact 62. Also, theplastic tube which comprises the casing can have an appropriate contour61 molded on its end, in accordance with the projected use to which itis to be placed. In FIGURE 3 is shown another embodiment in which thetubing 47 is clamped in a depression 58 on the inside surface of thecasing 55, by an appropriately shaped ring 57. Also, extension 51 on theopposite end of the casing 45, FIGURE 2, can be a seperate tube in anappropriate end closure. As shown, the conduit 52 is attached to areduced diameter portion 51 of the casing 45. It can also be the fulldiameter of the casing 45, with the conduit 52 adapted to connect withit in pressure tight relation. Or, if desired, the casing 45 can be oneend portion of a long flexible plastic tube or conduit 52. Theembodiments of FIGURES 2, 3, and 4, might be consldered as disposableinstruments, with the portions 46, 45, 47, 49 (and possibly 52) preparedand stored for use in sterile condition, and disposed of after use.

. In FIGURE 5 is shown another embodiment of this nvention in which twotubular probes are used, one lnside of the other. These are shownschematically in extraverted position, as tubing 66 fastened totermination 67, which is fastened to tubular casing 65. Similarly,tubing 69 is fastened to termination 70 which is fastened to tubularcasing 68. Casing 68 is of smaller diameter than 65 and is adapted to beinserted into 65 and to be centered and positioned by ring 71. There isone or more holes 72 drilled through ring 71 so that the space 73between the two casings 65, 68, can communicate with the space 91between the two probes 66, 69. The two probes at their closed ends arefastened together by means of a short tension member 76 attached by anydesired means to the closed ends 75, 77, of the probes 66 and 69,respectively.

The space 73 can be closed by an annular plug or seal, and the innercasing closed off in any desired way. However, I prefer to make thelengths of the casings 65, 68, such that their open ends are in oneplane. They are sealed against a resilient diaphragm 78 pressed againsttheir ends by end cap 79. Cap 79 is held to casing 65 by means notshown. It has two or more openings 80, 81, through which needles orsmall tubes 82, 84, can be pressed in such a manner that the compliantmaterial of 78 will seal them against pressure. Thus needle 82communicates with space 73 and 84 with space 74.

As in FIGURE 1, each of the needles or tubes 82 and 84 are connected byflexible conduits or tubing 83, and 85, respectively, to reservoirs 86,86', respectively. The reservoirs are adapted to tbe positionedvertically in accordance with arrows 90, 90, their position being shownby indexes 88, 88' placed along scales 89, 89, respectively.

In normal use, the probes will be introverted into the inner casing 68,space 74. The reservoirs 86, 86' are positioned to a negativeextraversion index (below the elevation of the instrument casing). Theyare filled with a suitable liquid. They are then both raised so thatliquid will flow into spaces 73 and 74, thus extraverting the probes tothe position indicated. It will be desirable to bleed air from thecasing by inserting suitable needles (as shown in my copendingapplication Ser. No. 498,462) through openings 92, 93, and throughdiaphragm 78 into spaces 74 and 73, respectively.

Now the probes are in fully extraverted condition and both reservoirsare at a positive extraverting index. If it is desired to retrieve theprobes, the reservoir 86 is maintained at its present level, and 86' islowered to a negative index. Thus, liquid will flow out of 74 and thetubing 69 faced with a higher pressure on its outside surface, in space91 than on its inside surface, in space 74, will be introverted at thetermination 70 and will be driven into casing 68, carrying with it (dueto the member 76) the outer tubing 66. The outer tubing 66 still has thesame pressure on it as before, so it will introvert at the remote end,in a manner which is the reverse of the process of extraversion. Thus,by control of the level of the two reservoirs, 86, 86, the probes can beextraverted or intraverted at will, without manual handling.

In FIGURE 6 is shown another embodiment. It is like FIGURE 5 in that ithas two eversible thin-walled flexible tubings, an outer tubing 100fastened to termination 102, and inner tubing .101 fastened totermination 103. The two terminations 102, 103, are sealed together todefine a fixed volume 104 inside of 100 and outside of 101. The ends ofthe two tubings 105, 106, are joined with a tension member 107. Meansare provided for sealing a fine needle 108 through the termination 102(or other siutable place) by means of which fluid can be introduced intospace 104. Consider that a fixed volume of liquid is placed in 104 todistend 100 to its maximum volume and collapse 101 to its minimumvolume. Thereafter the needle is removed and the opening sealed.

Means are provided to reduce the volume 104. This can be by manualsqueezing, or by such clamp means as the rails 109, 110, confining thesides of the tubing 100, (FIGURE 7) clamp frame 111 and thumb screw 112.As the volume 104 is reduced, the liquid forces the inner tubing 101 tobe extraverted through its termination 103 to the dotted position 101.As the inner tubing 101 moves out, its trailing end 106 pulls on tensionmember 107 which pulls on the end 105 of outer tubing 100. Thus, when101 moves to position 101, outer tubing correspondingly moves to dottedposition, with corresponding position When it is desired to retract orinvert the tubing 101' back to 101, the squeezing pressure by the rails.109, 110, is removed, and the fluid flows back from 113 to 104. Ifdesired, a tension member 114 tied to 105, can be used to pull back105', 107', and 106 and the inner tubing 101 to its fully invertedposition.

In FIGURE 8 is shown a modification of FIGURE 6 in which the volume 104is reduced, not by lateral squeezing, but by longitudinal shortening.The two tubings 120, 121 are similar and attached to terminations 122,123, respectively, which are part of a casing 124. The two tubings arejoined at their closed ends 128, 130, by tension member 129. The outertubing is also joined by clamp 126 to a rigid member or rod 127. Thevolume 104 is again filled through needle 125, as before, to provide afixed volume of liquid. By pushing on 127, the end of the outer tubing.120 is pushed in, reducing the volume 104, and forcing the inner tubingto be everted out of the termination 123. To retrieve the tubing 121after it has been everted, rod 127 is pulled, which pulls 129, 130', andtubing 121, forcing liquid back into 104 and 1engthening and enlargingthe volume of the outer tubing 120.

Referring again to FIGURE 5, it is possible to provide in the space 91,through needle 82, a polymerizing cement. Then, when the tubings areeverted, and pressed outward against the wall of the cavity, the surfaceof the tubing 66 will assume all of the convolutions of the innersurface of the cavity. This expanded condition is maintained until thecement has polymerized and binds the two tubings together. While thecement will hold them together, they can still be inverted to bewithdrawn from the cavity. After retrieval, they can be everted again toshow the contour of the cavity.

If desired a thin layer of this polymerizing compound can be placed onthe inner surface (before inversion) of the outer tubing 66, so thatwhen everted into the cavity and expanded to press on the walls, thepolymerizing material will harden to show the fine detail of thesurface. Another possibility is to make the outer tubing itself of apolymerizing material. Pressure inside of 69 will press the outer tubing66 against the cavity surface and hold it there while it hardens in theshape of the cavity walls.

One material that can be used for this purpose is Devcon, which ismanufactured by the Dow Chemical Company of Midland, Mich. However,there are many other plastic compositions of this sort described in theliterature which can be used to make a true replica of the inner surfaceof the cavity.

This invention is susceptible to a wide variety of embodiments, some ofwhich have been described, and many more of which will be obvious to onetrained in the art, and is not to be construed as being limited to thescientific apparatus and processes described above. The scope of thisinvention is limited only by the scope of the appended claims.

I claim:

1. A medical instrument for placing a long flexible tubular probe into atubular cavity comprising,

a tubular casing, an opening in a first end and a closure across thesecond end of said casing,

a collapsed thin-walled flexible tubing inside said casing, the innerend of said tubing closed, the outer end of said tubing sealedcircumferentially over said opening,

a reservoir containg liquid,

means to elevate said reservoir above and to lower said reservoir belowthe position of said casing, and

conduit means connecting the interior of said casing with saidreservoir,

whereby when said reservoir is raised above the position of said casingliquid will flow from said reservoir into said casing and out throughsaid opening, extraverting said tubing through said opening and whensaid reservoir is lowered below the position of said casing liquid willflow from said casing into said reservoir, thereby causing said tubingto be intraverted into said casing.

2. The medical instrument of claim 1 in which the closed end of saidtubing is connected to a tension member passing through and sealed intosaid end closure.

3. The medical instrument of claim 2 in which the closed end of saidcasing is sealed with a rigid closure and said tension member is sealedthrough said closure by means of a pressure gland.

4. The medical instrument of claim 1 in which said closure comprises awall of elastomeric material through which a small diameter cylindricalelement can be passed and sealed.

5. The medical instrument of claim 1 in which means are provided tobleed air from said casing as liquid flows into said casing.

6. The medical instrument of claim 2 in which said tension membercomprises a small diameter thick-walled tube sealed into the closed endof said tubing.

7. Medical apparatus for irrigating an elongated body cavity comprising,

a tubular member serving as a casing,

a length of collapsed thin-walled flexible tubing in said casing,

a first end of said tubing circumferentially sealed over a first end ofsaid casing, the second end of said tubsealed over a short perforatedplug,

a reservoir of liquid attached by conduit means to the second end ofsaid casing, and

means to vary the vertical spacing of said reservoir with respect tosaid casing,

whereby when said reservoir is raised above said casing liquid will flowfrom said reservoir into said casing, causing said tubing to be evertedfrom said casing, whereupon said liquid will flow from said casingthrough said tubing and through said plug into said cavity.

8. The medical instrument of claim 7 in which the said tubing is sealedcircumferentially to said casing by cement means.

9. The medical instrument of claim 7 in which the tubing is sealedcircumferentially to said casing by means of a clamping ring.

10. A medical instrument for extraverting a long tubular probe into anelongated constricted body cavity comprising, a first tubular casing, afirst thin-walled flexible evertible tubing closed at one end and sealedat its other end circumferentially to a first end of said first casing,said first tubing forming an extension of said first casing, a secondtubular casing inserted into and sealed to said first tubular casing, asecond thin-walled flexible everible tubing closed at one end and sealedat its other end circumferentially to the first end of said secondcasing, said second tubing forming an extension of said second casing,the closed ends of said two tubings joined with a tension member, afirst liquid reservoir means connected by conduit means to the interiorof said second casing, a second liquid reservoir means connected byconduit means to the space between the said first and second casings,and means to adjust the vertical positions of said first and secondreservoir means with respect to said instrument.

11. A medical instrument for placing and retrieving a thin-walledflexible tubing within an elongated constricted body cavity, comprising,

a tubular casing, at least part of which is flexible,

an opening in the first end of said casing,

the second end of said casing sealed with a flexible tubular closure,

a length of thin-walled flexible tubing inside said casing,

n first end of said tubing sealed circumferentially over said opening,

the second end of said tubing sealed against fluid flow through saidtubing,

means for introducing fluid into said casing, and

means for changing the outer contour of said casing to reduce theinternal volume of said casing,

whereby when the outer contour of said casing is changed and theinternal volume reduced, fluid is forced out of said casing through saidopening causing said tubing to be extraverted out of said opening.

12. The apparatus of claim 11 in which the closed end of said tubing isconnected by a tension member to said flexible tubular closure.

13. Apparatus as in claim 11 in which said means for changing the outercontour of said chamber comprises means for reducing the transversecross sectional area of said chamber.

14. Apparatus as in claim 11 in which said means for changing the outercontour of said chamber comprises means for forcing said flexibleclosure longitudinally into said chamber, thereby reducing the effectivelength of said chamber.

15. The method of everting a long flexible tubular probe into a tubularcavity from an apparatus in which said probe is placed inside of atubular casing, the inner end of said probe closed, the outer end ofsaid probe circumferentially sealed over one end of said casing, thesecond end of said casing closed, a reservoir of liquid connected byconduit to said casing, comprising the steps of,

placing said opening in said casing against the mouth of said cavity,

starting with the level of said reservoir below the level of saidcasing, elevating said reservoir above the level of said casing untilliquid flows from said reservoir into said casing, and

maintaining the raised level of said reservoir until sufficient liquidhas flowed into said casing to evert said probe from said casing intosaid cavity.

16. The method as in claim 15 with the added steps of leaving said probein said cavity for a finite time, and lowering said reservoir to a levelbelow that of said casing, whereby liquid will flow out of said casinginto said reservoir and retrieve said probe into said casing.

17. The method as in claim 15 with the additional steps of leaving saidprobe in said cavity for a finite time, keeping the elevation of saidreservoir above that of said casing and mechanically drawing said probeback into said casing, by retrieval means attached to the end of saidprobe, whereby said probe will progressively invert at the extremeportion inside said cavity until it is progressively retrieved into saidcasing.

18. An instrument for placing and retrieving a thinwalled flexibletubing within an elongated constricted cavity, comprising,

a substantially rigid tubular casing,

a first opening across a first end of said casing,

a first length of thin-walled flexible tubing inside of said casing,

a first end of said first tubing sealed circumferentially over saidfirst opening,

the second end of said first tubing sealed against fluid flow throughsaid tubing,

a second opening in the second end of said casing,

a second length of thin-walled flexible tubing,

a first end of said second tubing sealed circumferentially over saidsecond opening and extending longitudinally from said casing,

the second end of said second tubing sealed against fluid flow throughsaid tubing,

means for introducing fluid into the space inside said casing and insidesaid second tubing, and

means for changing the external configuration of said second tubing soas to reduce the internal volume of said second tubing,

whereby fluid is forced out of said second tubing through said firstopening, thereby extraverting said first tubing out of said firstopening.

19. Apparatus as in claim 18 in which said means to change the externalconfiguration of said second tubing comprises means to laterallycompress said second tubing to a reduced cross-sectional area.

20. Apparatus as in claim 18 in which said means to change the externalconfiguration of said second tubing comprises means for forcing saidsecond end of said second tubing longitudinally inside of itself andinto said casing.

21. Apparatus as in claim 20 in which said second tubing surrounds intight contact a long cylindrical member of diameter less than thediameter of said second opening, and said means for forcing said secondtubing into said casing comprises said long cylindrical member.

22. Apparatus as in claim 21 in which said long cylindrical membercomprises a rod-like cylindrical member.

23. Apparatus as in claim 18 in which the second ends of said first andsecond tubings are connected together.

24. A medical instrument for placing and retrieving a thin-walledflexible tubing within an elongated cavity comprising:

a tubular casing,

a first eversible tubing inside said casing, a first end of said firsttubing sealed circumferentially over a first end of said casing, thesecond end of said first tubing sealed against fluid flow through saidfirst tubing,

a second eversible tubing, a first end of said second tubing sealed overthe second end of said casing and extending longitudinally from saidcasing, the second end of said second tubing sealed against fluid flowthrough said second tubing,

means to fill said casing and said second eversible tubing with fluid,and

means to cause said second eversible tubing to invert and force fluidinto said first eversible tubing, thereby causing said first eversibletubing to evert.

25. Apparatus as in claim 24 including long slender cylindrical meansinserted into second end of said second eversible tubing, wherebypushing longitudinally on said cylindrical means will cause said secondeversible tubing to invert.

26. A medical instrument for placing and retrieving a thin-walledflexible tubing within an elongated constricted cavity, comprising,

a substantially rigid tubular chamber,

an opening across a first end of said chamber,

a length of thin-walled flexible tubing inside said chamber,

a first end of said tubing sealed circumferentially over said opening,

the second end of said tubing sealed against fluid egress,

the second end of said chamber sealed by a flexible tubing closure overthe said second end of said chamber,

means for introducing fluid into said chamber and into said flexibleclosure, and

means for pressing said flexible closure longitudinally into said secondend, forcing fluid longitudinally along said chamber and extravertingsaid tubing out of said opening.

References Cited UNITED STATES PATENTS 935,227 9/1909 Pfeifer et al.128-227 2,513,527 7/1950 Sjodin '264'165 3,168,092 2/1965 Silver-man128--1.2 3,178,732 4/1965 Stibitz 581 FOREIGN PATENTS 454,642 7/ 1928Germany.

DALTON L. TRULUCK, Primary Examiner.

US. Cl. X.R.

